牙本质表面处理对粘接性能的影响

Effect of dentin conditioning on bonding performance

目的探讨0.5mol/L乙二胺四乙酸(EDTA)和35%的磷酸以及前处理剂对受龋影响牙本质、正常牙本质与光固化复合树脂粘接密合性能的影响。方法实验用牙为拔除的患龋磨牙及正畸拔除的前磨牙各23颗,将受龋影响牙本质(CAD)和正常牙本质(CFD)分别用EDTA和磷酸处理,扫描电镜观察牙本质的超微结构。在离体牙标本上分别制备柱状牙本质洞形,分别经EDTA和磷酸处理后,再各取半数使用前处理剂甲基丙烯酸甘油单酯(GM)处理,全部样本用光固化复合树脂常规充填,光镜测量其洞底粘接断面最大收缩间隙,并对收缩间隙进行扫描电镜观察。结果EDTA和磷酸均能清除牙本质表面的玷污层,CAD表面的牙本质小管大部分被矿化结晶堵塞,EDTA不会使管周高钙化区脱钙;磷酸可使牙本质小管管周脱钙,使CFD牙本质小管呈喇叭口状开放,对CAD的矿化结晶体的影响不大。磷酸较EDTA处理牙本质的粘结断面出现的收缩间隙明显增加(P(0.05),GM前处理对于降低CFD与复合树脂之间的收缩间隙有明显作用(P(0.05),而对CAD与复合树脂之间的粘接无明显作用。结论EDTA处理牙本质可提高其与复合树脂之间的封闭性能。前处理剂GM可提高CFD与复合树脂之间的封闭性能,对CAD的作用不明显。对CAD适当的处理,亦可获得良好的粘接性能。

Objective To evaluate the effect of different dentin surface conditioning on bonding performance.Methods Twenty-three extracted teeth with caries-affected dentin and 23 teeth extracted for orthodontic purpose were included in this study.The caries-free dentin and the normal dentin were treated with 0.5 mol/l ethylenediamine tetraacetic acid （EDTA） and 35% phosphate acid,and the ultrastructure of the dentin was observed with scanning electron microscope.The cavity in the teeth was prepared and the dentin treated by EDTA and 35% phosphate acid respectively,and then restored with a commercial composite resin （Silux Plus） mediated with a commercial dentin bonding agent （Clearfil Photo Bond） with or without priming of 35vol% glyceryl mono-methacrylate （GM）.Results EDTA and phosphate acid all removed the smear layer of dentin,but over decalcification was observed in phosphate acid group.The contraction gap in the bonding surface increased more obviously in phosphate acid groups than in EDTA groups（P﹤0.05）.Sound cavity adaptation was observed in the specimens of both caries-free dentin priming with GM and caries-affected dentin priming with and without GM.Conclusion EDTA conditioning could improve the bonding between dentin and resin.Glyceryl mono-methacrylate enhanced the sealing between normal dentin and resin,but had little effect on caries-affected dentin.Caries-affected dentin could also get sound bonding with composite resin.